Recreational Vehicle. An RV Bill of Sale is a legal document that serves as proof of the sale and transfer of ownership of a recreational vehicle (RV) from a seller to a buyer.Division of Law Enforcement. RECREATIONAL. General Bill of Sale – This form would usually be used to provide proof of sale and purchase between two private parties in the sale of personal items. This is typically one of the first items you'll put on the bill of sale. A Massachusetts bill of sale form is a legal document used to record the sale of personal items in the state of Massachusetts.